A spokesperson from Swiss network provider Swisscom told Telecoms.com: "Apple only enables 4G access after testing their device on an operator's live network."
Swisscom launched its LTE network last week, and says that "Apple will provide a software update in due course" to make its 4G service compatible with the iPhone 5.
By carrying out tests on networks and being the one to give the final go ahead on whether to enable 4G services, Apple ensures that it has complete control over operators.
Apple's strict control "shocked" Bengt Nordstrom, founder and CEO at industry consultancy NorthStream, who told Telecoms that his company first found out about the network testing policy in October.
Nordstrom says that Apple's policy shows "who is running the industry". "Apple have put themselves in the driving seat; it's really changing the game," he added.